- increasing work hours is a one-time "boost". It gives a numbers bump once. It's not continued growth.
- working LESS has been shown time and time again to actually make workers more productive
- working more will mean even fewer children, a problem we desperately need to address and which will harm the economy even more in the long term
- our social contract is broken. Fixing the economy and the country can't be done by extracting more work from the working class. The decades-long profiteers from privatization and giga-profits need their stolen wealth ripped from them. I can not understate this point. Literally all our economical and most of our societal problems could be fixed relatively easily by spending money: repair infrastructure; properly fund and repair the Bahn; pay teachers enough to make the job attractive, fix up schools, make proper education available to everyone; pay higher wages, so parents can choose to only have one parent working, but also provide free Kitas; and so on. I even would go as far as to say that materially and directly improving people's lives like this would deal a blow to the rise of right wing politics and faschism, since a lot of those voters are simply frustrated with their misery and powerlessness (not all, obv...). A supposedly center-left party going "höh--höh, suck it, work more" does the opposite of this. And to get back to this bullet point: the money for ALL of that and more IS THERE. Just... Unjustly held by the few.
Now tell me again, why is it on me to spend additional years of my life toiling away to "fix" the economy when it's ineffectual, counterproductive down the line, and a much easier, more just solution exists?